Colorectal Cancer: Histopathologic Differences in Tumor Characteristics Between Patients With and Without Diabetes

Diabetes is associated with a greater risk and poorer clinical outcome in colorectal cancer. A review of 534 patients with colorectal carcinoma found worse histopathologic features at diagnosis in patients with diabetes in comparison with patients without diabetes. These histopathologic features are associated with poor prognosis in colorectal cancer and support the fact that diabetes is associated with a poorer prognosis in colorectal cancer. Background: Current literature suggests that diabetes is a possible predictor of risk and worse outcome in colorectal cancer (CRC). The objective of this study was to explore if there are histopathologic differences in CRC between populations with and without diabetes. Patients and Methods: Retrospective analysis was done on 534 patients with CRC. Patients were divided into diabetic and nondiabetic subgroups. Data were collected for lymphovascular invasion, tumor location, depth invasion, staging, level of differentiation, histologic type, and presence of tumor components (mucinous, signet ring, or neuroendocrine). Results: Univariately, patients with diabetes had deeper tumor invasion, greater lymphovascular invasion, and higher TNM staging (OR and 95% CI, 2.06 [1.37, 3.10], 2.52 [1.74, 3.63], and 2.45 [1.70, 3.52], respectively; P < .001). Covariate adjustment retained the significant effect of diabetes on tumor characteristics (P < .005). Multivariable adjustment significantly linked diabetes with signet ring cell carcinoma (log odds, 11.40 +/- 5.28; P=.03) and tumor components (log odds, 0.58 +/- 0.25; P=.02). Patients with diabetes with hyperlipidemia had more well-differentiated tumors (log odds, -0.96 +/- 0.47; P=.04). Transverse tumors were more common in patients with diabetes (log odds, 1.74 +/- 0.72; P=.02). Conclusion: Patients with diabetes had worse histopathologic CRC features. Hyperinsulinemia, insulin like growth factor receptor activation, and hyperglycemia in diabetes can activate mitogenic pathways stimulating proliferation, invasion, angiogenesis, and metastasis. Future research is needed to identify responsible pathways for targeted therapy and to examine the role of better glycemic control and treatment in patients with CRC and diabetes. (C) 2014 Elsevier Inc. All rights reserved.